1. Field of Invention
The invention relates to motor vehicle braking systems and anti-theft devices.
2. Description of the Prior Art
Parking brake systems for motor vehicles typically comprise a mechanical actuator within the passenger compartment which is mechanically connected to and operates hydraulic brakes. Such a system is commonly employed as a safety device wherein the operator engages the parking brake while the vehicle is stopped before exiting the vehicle. The intended result is to prevent the unattended vehicle from moving in the event that other primary braking systems might fail to prevent such movement.
One disadvantage of current hydraulic parking brake systems is that the physical properties of mechanical actuators utilizing differing materials renders the parking brake systems subject to restricted movement in extreme cold weather causing difficulty in actuating the parking brake.
In addition, various motor vehicle, anti-theft devices are commonly employed. Such devices either act to warn of impending intrusion to the vehicle, to ward off an intruder or, more germane here, to prevent the vehicle from being operated by persons other than those so authorized by the vehicle owner. Such operation-hindering devices are engaged to inhibit a specific vehicle control function, typically steering, from operating and are disengaged for authorized use. These devices are typically controlled by an actuator whose location in the vehicle is known only to those authorized by the owner or those that are difficult to disable without, for example, a key.
One disadvantage of current vehicle anti-theft devices is that they are typically connected to actuators within the passenger compartment of the vehicle, thereby increasing the possibility of being identified and disabled by an intruder.
A second disadvantage of current vehicle anti-theft devices is that they are an addition to the vehicle solely for the purpose of inhibiting or preventing theft, thereby increasing the overall cost of owning and operating the vehicle.
Finally, since the only purpose served by conventional anti-theft devices is to hinder or prevent theft, status indicators are typically either absent or are strategically, and therefore inconveniently, located in order to defeat detection by unauthorized users.
Accordingly, there is a need in the motor vehicle industry for a reliable Parking Brake Valve as an alternative to existing hydraulic parking brake actuator systems and/or as an integral, secure vehicle anti-theft device.